1. Technical Field
This invention relates to sealable food storage containers. More particularly, this invention relates to selectively sealing the food storage container and removing an amount of fluid from the container to keep food in the container under vacuum. Specifically, this invention relates to a food storage container having a lid assembly for removably receiving a valve insert having a vacuum indicator for visually indicating when a vacuum is present in the container.
2. Background Information
It is well known that food storage can be improved by keeping food in a container under vacuum. Keeping the food in a container under vacuum helps to prevent the food from spoiling as quickly as the food normally would under normal pressure. This is particularly important when dealing with infant food as a baby's digestive system and overall immunity has not developed to the point of having sufficient biological defenses pertaining to mildly oxidized or spoiled food. Thus, not only is it extremely important to provide a way to prevent baby food spoilage, it is also extremely important to ensure that the pieces and parts within such a container have been properly cleaned and sterilized as they may hold contaminants or particles of food which would be ingested along with the unspoiled food if the container is not properly cleaned. In addition, it is often not possible for the user to recognize when the desired vacuum is still present in the storage container. As such, a parent may believe a vacuum is present in a container when in fact the food in the container is not under vacuum.
Previous methods have been designed for keeping the food in the container under vacuum. For example, U.S. Pat. Nos. 5,195,427; 6,725,632; and 7,721,771 all propose devices using a vacuum pump for removing air pressure from a food storage container. However, the devices in this patent all are operated using a power supply for powering the vacuum pump. However, designs of this type have been found to be less desirable in that an electrical power outlet is constantly required to remove pressure from the container. Thus, it has been found that powered vacuum pumps and containers related to these devices are less desirable due to the inconvenience of powering the vacuum pump.
U.S. Pat. Nos. 5,546,997; 5,955,127; 6,035,769; 6,789,690; 7,048,136; 7,140,402; and 7,198,047 all describe food storage containers with a pressure release valve structure or method incorporated into the device for equalizing pressure within the container with respect to the outside of the container. This pressure release element allows a user to equalize pressure or release a vacuum without removing a lid from the container. However, including such a structure is costly as it adds complicated mechanical elements and materials to the overall structure of the container. Furthermore, this pressure release valve structure necessarily adds internal elements to the container itself, which increases the surface area and pockets for bacteria or other undesirable microorganisms to reside and oxidize, thus leading to quicker spoilage of the food and possible health complications. Therefore, a pressure release valve structure incorporated into a container has been shown to be an overall complicated and undesirable feature.
U.S. Pat. No. 6,675,982 describes a first valve and a second valve in the container lid for aiding in expelling air from the container. As described above, an additional valve or additional elements add to the complexity, expense, and safety to the overall container device. Thus, multiple valves within a container lid has been shown to be undesirable.
Finally, U.S. Pat. No. 6,131,753 describes another container evacuation system. This document shows a vacuum jar apparatus, including a bell jar and a vacuum pump lid, which both closes and seals the jar and pumps air out of the sealed jar. The lid includes a lower lid portion in the form of a sealing disk having a disk lower face covered with a sealing gasket material for extending across and sealing the jar upper rim. The lid lower portion also includes a downwardly extending circumferential lip for receiving the jar upper rim to center the lid on the jar. The vacuum jar apparatus of this document further includes a pumping mechanism for evacuating air in the form of either a wedge-shaped box having check valves and which permits air to be drawn from within the jar and exit the wing structure as a user turns the lid. A user wishing to permit air to enter the jar so that the lid can be removed from the jar pulls a finger engaging ring upward to sufficiently pull a cable taut, which then pulls the connected valve wall upward to emit air outside the apparatus through a vacuum release passageway into the jar. While this overall lid structure is encased in an outer shell, shown in FIG. 1, the internal mechanisms are elaborate and complex. As such, as described above, this complex valve mechanism coupled with a pressure release system is undesirable.